I have 11 Sonos devices. 9 are connect amps all connected via Ethernet and a switch to the router. 2 are Sonos 1s connected wirelessly. All of the Amps play nicely no matter the grouping, and can be added/removed/controlled perfectly. When I add the 1s to any group of Amps—-many problems. It struggles to get added to the group, requiring several tries. Once connected, problems adding songs to the queue, problems starting a station, and if it does start the 1s cut in and out.
I also have a playbar Ethernet cornnrcted and the Sub wireless.